JPH0716625A - Method and apparatus for controlling rolling mill - Google Patents

Abstract

PURPOSE:To suitably control disturbance even when a delay occurs in each actuator by detecting, storing the fluctuation of a plate thickness on the inlet of a mill and operating the hysterisis of a future fluctuation for feed-forward control. CONSTITUTION:The rolling-down position of a rolling stand 1, the rotating speed of a roll, the metal sheet thickness on the outlet side, the rear tension are detected by a state detector 3 to be inputted into a feedback control part 5. In this time, a control gain is set in accordance with a gain setting evaluation index inputted from an input part 10 in a gain setting part 7 and sent to the feedback control part 5. On one hand, the fluctuation of the sheet thickness on the inlet side of the mill is detected by an inlet side sheet thickness detector 4 and inputted into a sheet thickness storing part 8 on the inlet side at every prescribed sampling time to be stored as the future hysterisis. The sheet thickness data corresponding to predicted time outputted from it to the feed-forward control part 6. A rolling-down command and a roll speed command obtained by the feedback control part 5 and the feed-forward control part 6 are added by an addition part 9 to be outputted as a new rolling-down command, a roll speed command.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and method for disturbance fluctuation of a delivery thickness / back tension control system of a rolling mill.

[0002]

2. Description of the Related Art Conventionally, as a method for controlling the outgoing side plate thickness, which corresponds to the fluctuation of the incoming side plate thickness which is a noticeable disturbance on a rolling mill, for example, "Theory and practice of plate rolling" (Japan Iron and Steel Institute Joint Research Group, Rolling Theory Section) As described in Chapter 12 of the Iron and Steel Institute of Japan, there are methods called feed-forward AGC (Automatic Gauge Control) by rolling down operation and feed-forward AGC by roll speed operation. It was a proportional feedforward control in which each operation was performed in proportion to the thickness variation value. An example in which feedforward control and feedback control are combined is described in JP-A-61-189812.

[0003]

However, since each of the above-mentioned prior arts is proportional control focusing only on the inlet side plate thickness at the time of control, when the rolling down device or the roll speed device has a delay in response, sufficient disturbance is caused. There was a problem that it could not be controlled. Even if control is started at an earlier time than the response delay time, there is a problem that the response of the reduction device or roll speed device cannot follow the fluctuation of the entrance side plate thickness if the disturbance, that is, the speed of the entrance side plate thickness fluctuation is fast. It was

The object of the present invention is to reduce the thickness of a rolling mill, which can cope with a noticeable fluctuation of the incoming plate thickness as a disturbance entering the rolling phenomenon.
In tension control, appropriate disturbance control is realized even when each actuator has a delay.

[0005]

In order to achieve the above object, the present invention provides a controller for controlling a rolling mill having plate thickness and tension as controlled variables, and a rolling reduction device for changing the rolling state of the rolling mill. An actuator such as a rolling roll rotating device, an inlet side thickness variation detecting unit for detecting a thickness variation of a rolled material entering the rolling mill, an inlet side thickness storing unit for storing an output of the detecting unit, The input side plate thickness storage unit is configured to include a feedforward control unit that inputs a future variation history of the plate thickness stored in a predetermined time within a predetermined time and outputs a signal instructing an operation amount to the actuator. .

In order to achieve the above object, the present invention also provides a controller for controlling a rolling mill having plate thickness and tension as controlled variables, a rolling down device for changing a rolling state of the rolling mill, and a rolling roll rotating device. Actuator such as, an input side plate thickness variation detection unit for detecting a plate thickness variation of the rolled material entering the rolling mill, an input side plate thickness storage unit for storing the output of the detection unit,
A feedforward control unit for calculating and outputting a signal instructing an operation amount to the actuator by inputting a future fluctuation history of the plate thickness stored in the input side plate thickness storage unit within a predetermined time, and at least a rolling down of the rolling down device. A feedback control unit for calculating and outputting a signal instructing the operation amount to the actuator by inputting the position, the rotation speed of the rolling roll, the rear tension, and the exit side plate thickness, and in the calculation of the feedforward control unit and the feedback control unit. A gain setting unit that determines the control gain to be used, a response display unit that displays the exit side plate thickness and backward tension of the rolling mill, and a parameter for performing gain adjustment of the feedforward control unit and the feedback control unit are the gain. The configuration includes an input unit for inputting to the setting unit.

In order to achieve the above-mentioned object, the present invention also provides a control method for controlling a rolling mill having controlled amounts of a delivery side plate thickness and a rear tension, wherein the delivery side plate thickness, the rear tension, and a reduction in the rolling mill. The rolling position of the device, the rotation speed of the rolling rolls, and the procedure for obtaining the future history of the sheet thickness variation in the predetermined time width of the rolled material entering the rolling mill, the obtained outlet sheet thickness, the backward tension, the A rolling position of a rolling device in a rolling mill, a rotation speed of a rolling roll, and a procedure for obtaining an operation amount of an actuator that changes a rolling state of the rolling mill from a future history of sheet thickness fluctuations in the predetermined time width, and the obtained actuator. Procedure of operating the actuator using the operation amount of, and a procedure of adjusting the operation amount obtained in the procedure based on the response waveform of the exit side plate thickness and backward tension of the rolling mill It is obtained by configured to include.

In order to achieve the above-mentioned object, the present invention also provides a rolling mill control method for controlling actuators such as a rolling mill rolling down device and rolling roll rotating device by using plate thickness and tension as controlled variables. A procedure for detecting the thickness variation of incoming rolling material at a sampling interval set at a predetermined position on the upstream side of the rolling roll, and the detected multiple thickness variation values as future thickness variation history. A sequence of storing the sequence, a sequence of calculating and outputting a first signal indicating the operation amount to the actuator with the stored future thickness variation history as an input, and at least a rolling position of the rolling device. A procedure of calculating and outputting a second signal for instructing the operation amount to the actuator by inputting the rotation speed of the rolling roll, the rear tension and the exit side plate thickness, and adding the first signal and the second signal The obtained signal is obtained by constituting and a procedure for the control signal of the actuator.

[0009]

[Function] The fluctuation of the incoming plate thickness of the rolling stand with the rolling mill is
It is detected at a predetermined sample time by the inlet side plate thickness variation detecting section arranged on the upstream side of the rolling roll, and is stored in the inlet side sheet thickness storage section as a future history of the inlet side sheet thickness variation in time series.
When a certain point of the rolled material in which the sheet thickness variation is detected and stored reaches a predetermined position, the future history of the sheet thickness variation from that point to the point which reaches the predetermined position after n sample time is the entrance side sheet thickness memory. From the rolling section and sent to the feedforward control section, where the feedforward control uses time-series sheet thickness fluctuations up to n sampling time after the sheet thickness fluctuations of the rolled material flowing immediately below the roll. From this, a reduction command and a roll speed command are calculated as the first signal. For this reason, the actuator is not controlled based on the strip thickness variation data for each point of the rolled material, but the strip thickness variation over a certain range in the future is predicted, and the deviation from the planned value of the outlet strip thickness in the certain range is detected. The actuator is controlled so as to minimize it. Therefore, the response of the actuator does not follow the plate thickness variation at a certain point of the rolled material, but follows the plate thickness variation over a certain range in the future. Becomes smaller, and the cumulative amount of deviation of the outlet plate thickness also becomes smaller.

Further, the second position signal for instructing the operation amount to the actuator is calculated and output by the feedback control by inputting the reduction position of the reduction device, the rotational speed of the rolling roll, the backward tension and the outlet plate thickness, and the first signal is output. By using the signal obtained by adding the 1st signal and the 2nd signal as the signal instructing the operation amount to the actuator, the control accuracy is further improved.

[0011]

[Embodiments] Hereinafter, control of delivery side plate thickness and backward tension of a cold tandem rolling mill according to an embodiment of the present invention will be described. Figure 2
FIG. 3 is a diagram showing an outline of a tandem rolling mill that is the control target. In FIG. 2, each stand 21 of the tandem rolling mill is shown.
As an actuator, the roll 2 of each stand 21
A roll speed device 25 for rotating the roll 3 and a reduction device 22 for moving the roll up and down are provided. Reduction device 22
Is operated, the load applied to the material to be rolled 24 changes, which affects the rolling phenomenon and affects the stand outlet side plate thickness and the stand rear tension. When the rolling roll speed device 25 is operated, the rotation speed of the roll 23 changes. Then, the change in the rotation speed of the roll 23 affects the speed difference between the stands, the tension between the stands changes, and the rolling situation is affected. Further, the plate thickness of the material to be rolled 24 flowing out from the i stand 21-1 is detected by the plate thickness gauge 26 on the output side. Then, this plate thickness becomes the entrance side plate thickness of the next i + 1 stand 21-2. That is, rolling mill i + 1 stand 21-
The entrance-side plate thickness disturbance in 2 is a known disturbance.

FIG. 1 is a block diagram showing a main part of a control device in which the present invention is applied to control of a strip thickness / rear tension of a tandem rolling mill. The rolling mill to be controlled in FIG.
As shown in FIG. 2, it comprises a rolling stand 1 and two actuators 2 for controlling the rolls of the rolling stand 1 such as a roll speed device and a rolling down device.

The control device comprises a state detector 3, a feedback control section 5 connected to the output side of the state detector 3,
Gain setting section 7 connected to the feedback control section 5
And an input unit 10 connected to the input side of the gain setting unit 7.
And an inlet-side plate thickness variation detecting section (hereinafter referred to as an inlet-side sheet thickness detecting section) 4 for detecting an inlet-side sheet thickness variation of the rolling stand 1.
An input side thickness storage section 8 connected to the output side of the input side thickness detection section 4, and a feedforward control section 6 connected to the output side of the input side thickness storage section 8 and the gain setting section 7.
And an adder unit 9 connected to the output side of the feedforward control unit 6 and the feedback control unit 5, and a response display unit 11 connected to the output side of the state detector 3. The output side of the adder is connected to the actuator 2. Further, information on the roll speed is also input to the entry side thickness storage unit 8.

Next, the operation of the apparatus having the above configuration will be described.
The state detector 3 detects a rolling position, which is a state quantity of the rolling stand 1, a roll rotation speed, and a delivery side plate thickness and a rear tension which are also control amounts. The detected state quantity is input to the feedback control unit 5. At this time, in the gain setting unit 7, the control gain is set based on the gain setting evaluation index input as a parameter for calculation from the input unit 10, and the set control gain is sent to the feedback control unit 5. Has been. Then, in the feedback control unit 5, the input rolling position, roll rotation speed,
The reduction command and the speed command are determined based on the delivery side plate thickness, the rear tension, and the control gain, and are output to the addition unit 9.

On the other hand, the sheet thickness fluctuation, which is the inlet side sheet thickness disturbance of the material to be rolled which flows into the rolling mill, is detected by the inlet side sheet thickness detecting section 4 arranged at a predetermined position on the upstream side of the rolling roll. The plate thickness data detected by the entrance side plate thickness detection unit 4 is input to the entrance side plate thickness storage unit 8 every predetermined sampling time. The incoming side plate thickness storage unit 8 predicts the incoming side plate thickness variation data input from the incoming side plate thickness detection unit 4 and the predicted time when the material to be rolled at the point where the data is detected reaches the roll of the rolling stand 1 (the predicted arrival time). ) Are combined and accumulated as a future history of the inlet side plate thickness variation. Since the distance between the incoming side plate thickness detecting unit 4 and the rolling rolls of the rolling stand 1 and the speed at which the material to be rolled flows are known, it is input to the incoming side plate thickness storage unit 8 at a certain point (detected by the incoming side plate thickness detecting unit 4). The predicted time when the portion of the material to be rolled having the obtained data reaches the roll of the rolling stand 1 can be easily estimated. When the estimated arrival time tk stored in the entry side thickness storage unit 8 and the current time become the same,
Plate thickness data (H (k)) corresponding to the predicted time tk from the incoming side plate thickness storage unit 8 and plate thickness data (H (k + 1) stored in the incoming side plate thickness storage unit 8 after the predicted time and reached.
~ H (k + n)) is output to the feedforward control unit 6.

In the gain setting section 7, the control gain is set on the basis of the gain setting evaluation index input from the input section 10, and the set control gain is sent to the feedforward control section 6. The feedforward control unit 6 determines the history of the incoming side plate thickness variation (H (k) to H (k + n)) sent from the incoming side plate thickness storage unit 8 and the control gain sent from the gain setting unit 7. A reduction command and a roll speed command are obtained based on the output and output to the addition unit 9. The reduction command and the roll speed command obtained by the feedback control unit 5 and the feedforward control unit 6 are added by the addition unit 9, and new reduction command Sp (K) and speed command Vp (K) are added.
Is output as.

The rolling-down command Sp (K) obtained by the adder 9
And the roll speed command Vp (K) are input to the rolling down device and the rolling device of the actuator 2, and the rolling stand 1
Is operated by the actuator 2 based on these signals. The operation amount of the actuator 2 is adjusted by adjusting the control gains of the feedback control unit 5 and the feedforward control unit 6. The control gain is judged to be appropriate from the response waveforms of the outlet stand thickness and the backward tension displayed on the response display unit 11, and the gain setting evaluation index as a calculation parameter input from the input unit 10 is changed. Adjustments are made.

FIG. 3 is an internal detailed view of the entry side plate thickness storage section 8 in FIG. 1 of the embodiment of the present invention. Entry side thickness storage section 8
Is a sampler 804 to which the data from the entrance side plate thickness detection unit 4 is input, an arrival time prediction unit 801 connected to the sampler 804, and an estimated arrival time storage unit 802 connected to the arrival time prediction unit 801. A disturbance output unit 803 connected to the sampler 804, and a disturbance output unit 805 connected to the sampler 804, the estimated arrival time storage unit 802, and the thickness storage unit 803. 8
Reference numeral 05 is connected to the feedforward control unit 6, and the inter-stand plate speed data is input to the arrival time prediction unit 801.

In the entrance side plate thickness storage section 8 having the above construction,
The entrance side plate thickness detected by the entrance side plate thickness detection unit 4 is first input to the sampler 804, sampled at an actual control cycle, and the entrance side plate thickness disturbance H (k +
m) and the sampling time T (k + m) are output from the sampler 804. The sampling time T (k + m) that is the output of the sampler 804 is input to the arrival time predicting unit 801, and the arrival time predicting unit 801 detects the rolled material having the plate thickness disturbance H (k + m) detected at the sampling time. Estimate the time t (k + m) when the part reaches just below the roll of the rolling mill. The arrival time is calculated by the flowing speed of the material to be rolled, since the distance from the entrance side plate thickness detection unit 4 to just below the roll of the rolling stand is constant. For example, the distance between the entrance side plate thickness detection unit 4 and the position just below the roll of the rolling stand is set to L (m)
And the strip speed of the rolled material at the sampling time is Vm (m / se
c). At this time, the sampled thickness disturbance is predicted to reach just below the roll of the rolling mill after the time ta (sec) obtained by the following mathematical formula 1.

[0020]

## EQU1 ## ta = L / Vm The plate speed Vm can be directly input from the plate speed meter,
The plate speed formula known from the roll speed VR Vm = VR (1
+ F) (f: advanced rate). From the above, the time t (k + m) at which the detected sheet thickness disturbance H (k + m) reaches just below the roll of the rolling mill is expressed by the following mathematical formula 2.

[0021]

## EQU00002 ## t (k + m) = T (k + m) + ta arrival prediction time t (k obtained by the arrival time prediction unit 801
+ M) is stored in the estimated arrival time storage unit 802, and the sampler 804
The plate thickness disturbance H (k + m) sampled in (1) is stored in the plate thickness storage unit 803 in association with each other.
The predicted arrival time t (k + m) and the plate thickness disturbance H (k + m) are arranged and stored in the order of sampling. Estimated arrival time t (k +) stored in estimated arrival time storage unit 802
m) and the sample time T (k
+ M) is input to the disturbance output unit 805, and the sampler 804
Arrival time t same as sample time T (k + m) from
The plate thickness disturbance H (k) corresponding to (k) is selected from the plate thickness storage unit 803. Then, the plate thickness disturbance H at the sample point
(K) to thickness disturbance after n sample times, thickness disturbance data from H (k + n) (H (k), H (k + 1), ...
H (k + n)) is output to the feedforward control unit 6.

FIG. 4 is an internal detailed diagram of the feedforward control unit 6 in FIG. 1 according to the embodiment of the present invention. The feedforward control unit 6 includes multiplication units 11, 12, ... 1n.
, Multiplying units 21, 22, ... 2n, and the multiplying unit 11,
Adder unit 603 for totaling outputs of 1 ... 1n and outputting as a rolling-down command and adding unit 6 for adding outputs of the multiplying units 21, 22, ... 2n and outputting as a roll speed command.
04 and 04 are included. Multipliers 11, 12, ...
1n is the thickness disturbance data (H (k), H (k + 1), ..., H (k + n) output from the input side thickness storage unit 8 and the gains Kd11 and Kd12 output from the gain setting unit 7. , ...
..., Kd1n are multiplied and output to the addition unit 603, and the multiplication units 21, 22, ... 2n are used for the plate thickness disturbance data (H) output from the input side plate thickness storage unit 8.
(K), H (k + 1), ..., H (k + n), and the gains Kd21, Kd22, ..., Kd2n output from the gain setting unit 7.
Are respectively multiplied and output to the addition unit 604.

The calculation results of the adders 603 and 604 are output to the adder 9 as a rolling reduction command and a roll speed command, respectively.

Next, the gain setting section 7 in FIG. 1 will be described. The gain setting unit 7 sets the control gains of the feedback control unit 5 and the feedforward control unit 6 based on the gain design evaluation index input from the input unit 10. First, a model of a rolling mill which is a control target necessary for designing a control system will be shown. A model of a cold tandem rolling mill is, for example, a rolling load formula expressing a rolling phenomenon, an advanced rate, which is described in "Design of Control System by Numerical Analysis Method (Ando et al., Japan Society of Instrument and Control Engineers)". It can be expressed by a state space model derived from a formula, a tension formula, a gauge meter formula, and the like. In this state space model, each stand roll down position Si, each stand roll speed VRi, each stand rear tension τbi as a state quantity, each stand roll down position command Spi as each manipulated variable, each stand roll speed command Vpi, each stand output as a control amount. Side plate thickness hi, rear tension of each stand τb
i, can be expressed by using the stand-in side plate thickness Hi as the disturbance (where i represents the stand number).

In addition, the tandem rolling mill, which is a large-scale system composed of a plurality of stands, says, "Development of a blocked non-interfering optimal control system for mill control (The Institute of Electrical Engineers of Japan, Information Processing Research Group Material IP-87-11, p 101, Showa 62-1
1, Katayama et al.) ”For each stand. The actual control is discrete time control that changes the command at every sampling time. Therefore, the model of the final rolling mill is represented in discrete time and can be described by the following equations 3 and 4.

[0026]

[Equation 3]

[0027]

[Equation 4]

Here, in order to secure the disturbance rejection characteristic to some extent by the feedback control unit 5, a state equation of the error system as shown in the following Equation 5 is created. The error system can be created by, for example, “asymptotic characteristics of the optimum preview control system (Proceedings of the Society of Instrument and Control Engineers Vol. 25, No. 10,
P. 1083/1090 (1989), Kawamura et al.) ”.

[0029]

[Equation 5]

In × n is an n × n identity matrix, and 0n × m is an n × m zero matrix. T at the end of [] indicates a transposed matrix.

The feedback control section 5 is first designed for such a control target. Here, the design guideline is to minimize the quadratic form evaluation function J of the following formula 6.

[0032]

[Equation 6]

The parameters input from the input unit 10 when the gain setting evaluation index of Equation 6 is used are matrices Qi and Ri.
Is. The physical meanings of the elements q1 to q5 and r1 and r2 of the matrix at this time are as follows.

Q1: Weight for adjusting response of deviation from target delivery thickness of rolling mill 1 q2: Weight for adjusting response of deviation from target rear tension of rolling mill 1 q3: Response of rolling position of rolling mill 1 Q4: Weight for adjusting the roll speed response of rolling mill 1 q5: Weight for adjusting the backward tension response of rolling mill 1 r1: Weight for adjusting the magnitude of the command to the rolling down device of rolling mill 1 r2: Weight for adjusting the magnitude of the command to the roll speed device of the rolling mill 1. Therefore, in this case, the gain adjustment of the feedback control unit 5 and the feedforward control unit 6 can be performed by the following method. .

Slow response of outgoing side plate thickness deviation in response display section 11 → Increase q1 Response of rear tension deviation is slow in response display section 11 → Increase q2 ・ ・ ・ Now, based on the evaluation index of Equation 6 Then, the following control gain Ko calculated by the gain setting unit 7 is sent to the feedback control unit 5. Then, in the feedback control unit 5, the manipulated variable calculation described in Expression 7 is performed.

[0036]

[Equation 7]

Next, a method of designing the control gain of the feedforward control unit 6 for further minimizing the evaluation function of Expression 6 in addition to the feedback control of Expression 7 will be described. The operation amount calculation of the feedforward control unit 6 is described by Expression 8 in which the history of the inlet side plate thickness variation is multiplied by the gain and added.

[0038]

[Equation 8]

Here, when performing the feedforward control of Expression 8, the gain setting section 7 obtains the control gain Kdj used in Expression 8 so as to further minimize the evaluation function of Expression 6. The method of obtaining the control gain Kdj is derived from the condition of the following Expression 9.

[0040]

[Equation 9]

The control gain at this time is described by the following expression 10.

[0042]

[Equation 10]

In this way, with respect to the weighting matrix of the evaluation function input from the input unit 10, the gain setting unit 7 calculates
As shown in 0, the control gain Kdj of the feedforward control unit 6 is calculated and output to the feedforward control unit 6.

FIG. 5 is a flowchart showing the method of feedforward disturbance control according to the present invention. First,
step. In order to determine the evaluation function J shown in Expression 6 as 1, the evaluation function weighting matrices Q and R are input from the input unit 10. Next, step. As 2, the gain setting unit 7 calculates the control gain Ko of the feedback control unit 5 and the control gain Kdj of the feedforward control unit 6 by using the input weighting matrices Q and R, and the feedback control unit 5 and the feedforward control unit Output to the unit 6. Up to ste
p. 1 and step. 2 is the pre-processing, and the following steps. Three
~ Step. Step 7 is performed every sampling period of the entrance side plate thickness.

First, step. In 3.1, the inlet side plate thickness variation is detected by the inlet side plate thickness detecting unit 4, and step. State detector 3 in 3.2
The rolling state is detected by. Then, step. In 4,
The entry side thickness storage unit 8 predicts the time at which the detected thickness reaches just below the roll of the rolling stand. step.
In step 5, step. Plate thickness detected in 3.1 and step. The estimated arrival time predicted in 4 is additionally stored in the entry side thickness storage unit 8 as a history of future disturbance. step. In 6.1, step. The incoming side thickness variation from the incoming side thickness disturbance, which is the same predicted arrival time as the time detected in 3.1, to the time after n sampling time is taken out from the incoming side thickness storage unit 8 and fed to the feedforward control unit 6. Output, step. The feed-forward control gain Kdj calculated in 2 and the product-sum calculation as in Expression 8 are performed to calculate the feed-forward control manipulated variable Δu (k).

Then, step. In 6.2, step. The rolling position, the roll rotation speed, and the backward tension, which are the rolling states detected in 3.2, are output to the feedback control unit 5, and step.
The feedback control gain calculated in 2 and the calculation as in Expression 7 are performed to calculate the feedback control operation amount. Last step. In step 7, step. 6.1 and step. The manipulated variables calculated in 6.2 are added, and the actuator 2 of the reduction device and roll speed device is operated based on the obtained manipulated variables. Above step. 3 to step. Up to 7 are performed in one control cycle, and when these operations are completed, st is again set in the next control cycle.
ep. 3 to step. Up to 7 is repeated. Then, the exit side plate thickness and the backward tension of the rolling stand 1 obtained as a result of the above control are step. At 0 the response is displayed. At this time, if the response waveform is bad (for example, the plate thickness deviation is large), the parameters of the weighting matrix of the evaluation function are changed in the same manner as described above, and the feedback control gain and the feedforward control gain are newly determined.

FIG. 6 shows the case where the feedforward control and feedback control using the history of future disturbances are used as in the present invention, and the feedforward control and the feedback control using only the current disturbance value as in the conventional case. It is the figure which showed the result of having simulated the response of the output side board thickness of the rolling mill at the time of using. Here, as the conventional feedforward disturbance control, a method in which only the current inlet side plate thickness is reflected in the feedforward operation is used. As an example of the present invention, the inlet side plate flowing into the rolling mill after four steps in sampling time is used. The method of using the thickness up to the future history was used.
As a result, it can be seen that the maximum amplitude of the entrance side plate thickness can be reduced by the present invention. Also, using future disturbance values,
Moreover, since the delay of each actuator is taken into consideration, it can be seen that the actuator operates before the disturbance enters the rolling stand, and the variation of the thickness of the outgoing side thickness is suppressed.

FIG. 7 is an internal detailed view showing another configuration example of the entry side plate thickness storage section 8 in FIG. 1 of the embodiment of the present invention.
The illustrated input side plate thickness storage unit 8 includes a sampler 804-2, a plate thickness storage unit 803 connected to the sampler 804-2,
A disturbance output unit 805 connected to the plate thickness storage unit 803 is included, and the disturbance output unit 805 is connected to the feedforward control unit 6 and the sampler 804-2 is connected to the entrance side plate thickness detection unit 4. ing. The plate thickness storage unit 803 is a number (n = Ls) determined from the distance (Lstd) between predetermined stands and the distance (Lh) of the rolled material flowing at the sampling time.
td / Lh) thickness memory 806 that stores thickness data
-1 to 806-n. Such a thickness memory 80
In 6, the plate thickness data of the rolled material between the predetermined rolling stands in the longitudinal direction is stored in order. Therefore, the plate thickness memory 806
The entrance side plate thickness disturbance data stored in −n means the entrance side plate thickness of the next stand.

The entrance side plate thickness storage section 8 shown in FIG. 7 operates as follows. First, the entrance side plate thickness disturbance detected by the entrance side plate thickness detection unit 4 is input to the entrance side plate thickness storage unit 8. In the input side plate thickness storage unit 8, the input input side plate thickness disturbance is input to the sampler 804-2, is sampled at an actual control cycle, and the input side plate thickness disturbance H (k + m) is sampled at each sampling time from the sampler 804-2. Is output. At this time, the incoming side plate thickness disturbance data stored in the plate thickness memories 806-1 to 806-n of the plate thickness storage unit 803 is the sampler 804-2.
Are sequentially stored in the next thickness memory 806 at the timing of sampling. That is, the incoming side plate thickness disturbance data stored in the plate thickness memory 806-n is discarded, and the incoming side plate thickness disturbance data stored in the plate thickness memory 806-n-1 is stored in the plate thickness memory 806-n. Remembered. As described above, finally, the plate thickness memory 806-2 stores the input side plate thickness disturbance data stored in the plate thickness memory 806-1, and the input side plate thickness disturbance data H output from the sampler 804-2. (K + m) is the thickness memory 8 of the thickness storage unit 803.
No. 06-1 is stored.

As described above, the incoming side plate thickness disturbance data (H (k + n) to H (k)) stored in the plate thickness memories 806-1 to 806-n of the plate thickness storage unit 803 are collected at every sampling timing. Is output to the feedforward control unit 6 via the disturbance output unit 805, and at the same time, the plate thickness memory 80
The entry side thickness disturbance data H (k) stored in 6-n is discarded and the subsequent data is sent in sequence.

The future history of the plate thickness is output to the feedforward controller 6 by the above method.

In the above embodiment, J shown in Equation 6 is used as the evaluation function for determining the control gain, but in addition, the following, which is a modified example of Equation 6, may be used.

[0053]

[Equation 11]

Further, the evaluation function of Expression 6 may be generalized to the following Expression 12.

[0055]

[Equation 12]

From the plate thickness disturbance H, the outgoing plate thickness h and the tension τ
When the H ∞ norm expressing the transfer gain to b is used as the evaluation function, the following formula 13 is obtained.

[0057]

[Equation 13]

[0058]

According to the present invention, the inlet side plate thickness variation of a stand with a rolling mill is detected by the inlet side plate thickness detecting section, and is stored in the inlet side plate thickness storage section as a future history of the inlet side plate thickness variation. Each time the rolled material at a certain point stored under each roll is stored just under the roll, the future history of the sheet thickness variation from that point to the point just under the roll after n sample time is retrieved from the entry side thickness storage section. Is sent to the feedforward control unit, and the feedforward control unit calculates the rolling reduction command and the roll speed command using the plate thickness fluctuation until the n sampling time after the plate thickness fluctuation of the rolled material flowing immediately below the roll. By doing so, the control is performed in consideration of the delay of the rolling down device and the roll speed device, so that appropriate disturbance control can be realized even when each actuator has a delay.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of a control device of the present invention.

FIG. 2 is a conceptual diagram showing a schematic configuration example of a rolling mill that is a control target of the control device of the present invention.

FIG. 3 is a block diagram showing details of a portion of the embodiment shown in FIG.

FIG. 4 is a block diagram showing details of another portion of the embodiment shown in FIG.

FIG. 5 is a flowchart showing an embodiment of the control method of the present invention.

FIG. 6 is a diagram showing a comparison of the results when the present invention is used and when the conventional technique is used.

FIG. 7 is a block diagram showing details of another example of the portion of the embodiment shown in FIG.

[Explanation of symbols]

1 Control Target (Rolling Stand) 2 Actuator 3 State Detector 4 Input Side Plate Thickness Detection Section 5 Feedback Control Section 6 Feedforward Control Section 7 Gain Setting Section 8 Input Side Plate Thickness Storage Section 9 Addition Section 10 Input Section 11 Response Display Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Morooka 7-1, 1-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Yu Saito 5-2, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Incorporated company Hitachi, Ltd. Omika factory (72) Inventor Yasunori Katayama 5-2-1 Omika-cho, Hitachi city, Ibaraki prefecture Hitachi information control system (72) Inventor Masaaki Nakajima Hitachi city, Ibaraki prefecture 5-2-1 Omika-cho, Hitachi Ltd. Omika Factory (72) Inventor Satoshi Hattori 5-2-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Omika Factory (72) Inventor Toshiyuki Kashiwagi 5-2-1 Omika-cho, Hitachi-shi, Ibaraki, Ltd. Omika factory, Hitachi Ltd.

Claims (13)

[Claims] 1. A control device for controlling a rolling mill having plate thickness and tension as controlled variables, wherein an actuator such as a rolling device for changing the rolling state of the rolling mill, a rolling roll rotating device, and the like are installed in the rolling mill. Incoming side plate thickness variation detecting section for detecting the sheet thickness variation of the coming rolled material, an incoming side sheet thickness storing section for storing the output of the detecting section, and a sheet thickness stored in the incoming side sheet thickness storing section within a predetermined time. A rolling mill control device, comprising: a feedforward control unit that inputs a future change history and outputs a signal instructing an operation amount to the actuator. 2. A control device for controlling a rolling mill having plate thickness and tension as controlled variables, wherein an actuator such as a rolling device for changing the rolling state of the rolling mill, a rolling roll rotating device, and the like are installed in the rolling mill. Incoming side plate thickness variation detecting section for detecting the sheet thickness variation of the coming rolled material, an incoming side sheet thickness storing section for storing the output of the detecting section, and a sheet thickness stored in the incoming side sheet thickness storing section within a predetermined time. A feedforward control unit that outputs a signal indicating an operation amount to the actuator by inputting a future change history, and at least a reduction position of the reduction device, a rotation speed of a rolling roll, a rear tension, and an outlet plate thickness are input. A feedback control section for calculating and outputting a signal instructing an operation amount to the actuator, and a control used for calculation of the feedforward control section and the feedback control section A gain setting unit that determines the gain,
It comprises a response display section for displaying the exit side plate thickness and backward tension of the rolling mill, and an input section for inputting parameters for performing gain adjustment of the feedforward control section and the feedback control section to the gain setting section. Rolling mill control device. 3. The gain setting unit uses a method for minimizing a quadratic evaluation function of a rolling position, a rolling roll rotation speed, and a tension as a calculation method for obtaining a gain. Rolling mill control device described. 4. A feed-forward control unit for determining an operation amount of an actuator such as a rolling device or a rolling roll rotating device from a future fluctuation history of a plate thickness fluctuation of a rolled material entering a rolling mill within a predetermined time, and the rolling reduction. A feedback control unit that determines the operation amount of the actuator by inputting the rolling position of the device, the rotation speed of the rolling roll, the rear tension, and the outlet plate thickness, and the gains of the feedforward control and the feedback control are based on the same evaluation guideline. A rolling mill control device comprising a gain setting unit that is determined by 5. A control method for controlling a rolling mill, which uses a delivery side plate thickness and a backward tension as control amounts, wherein the delivery side plate thickness, the backward tension, a rolling position of a rolling down device in the rolling mill, a rotation speed of a rolling roll, and From the future history of the sheet thickness fluctuation of the rolled material entering the rolling mill in the predetermined time width, the operation amount of the actuator that changes the rolling condition of the rolling mill is obtained, and the response of the outgoing plate thickness and backward tension of the rolling mill is obtained. A rolling mill control method comprising adjusting an operation amount based on a waveform. 6. A method for controlling a rolling mill, which controls actuators such as a rolling mill rolling device and a rolling roll rotating device by using the sheet thickness and tension as controlled variables, the variation of the sheet thickness of the rolled material entering the rolling mill is controlled. Detected at a predetermined sampling interval at a predetermined position on the upstream side of the rolling roll, the plurality of detected plate thickness fluctuation values are stored in time series as a future plate thickness fluctuation history, and the stored future plate is stored. A first signal for instructing the operation amount to the actuator is calculated and output by inputting the thickness variation history, and further, at least the reduction position of the reduction device, the rotation speed of the rolling roll, the rear tension, and the delivery side plate thickness are input. A method for controlling a rolling mill, wherein a second signal indicating an operation amount to an actuator is arithmetically output, and a signal obtained by adding the first signal and the second signal is used as a control signal for the actuator. 7. A method of controlling a rolling mill, which controls actuators such as a rolling mill rolling device and a rolling roll rotating device by using plate thickness and tension as controlled variables, and a variation in plate thickness of a rolled material entering the rolling mill. Detected at a predetermined sampling interval at a predetermined position on the upstream side of the rolling roll, the plurality of detected plate thickness fluctuation values are stored in time series as a future plate thickness fluctuation history, and a preset evaluation function and A plurality of control gains are calculated based on a numerical value input as a parameter of the evaluation function, and a part of the calculated control gains and the stored future thickness variation history are input to operate the actuator. The first signal indicating the amount is calculated and output, and at least the rolling position of the rolling device, the rotation speed of the rolling rolls, the rear tension, the outlet plate thickness, and another part of the calculated control gain are input. In a rolling mill, a second signal indicating the operation amount to the actuator is output as a force, and a signal obtained by adding the first signal and the second signal is used as a control signal to the actuator. Control method. 8. The method for controlling a rolling mill according to claim 7, wherein the control signal to the actuator is adjusted by changing a numerical value input as a parameter of the evaluation function. 9. The rolling mill according to claim 8, wherein the exit side plate thickness and the backward tension of the rolling mill are displayed, and the numerical values input as the parameters of the evaluation function are changed based on the display. Control method. 10. A variation history of a sheet thickness variation of a rolled material entering a rolling mill within a predetermined time, a rolling position of a roll rolling device of the rolling mill, a rotation speed of a rolling roll, a rear tension, and a delivery plate. A rolling mill control method, wherein an operation amount of an actuator such as the roll reduction device or rolling roll rotating device is determined from a thickness and a control gain determined from a rolling mill model. 11. A feed-forward control for determining an operation amount of an actuator such as a reduction device or a rolling roll rotation device from a variation history of a variation in plate thickness of a rolled material entering a rolling mill within a predetermined time, and a reduction device of the reduction device. The thickness disturbance is controlled by the feedback position that determines the operation amount of the actuator from the rolling position, the rotation speed of the rolling roll, the rear tension, and the outlet side plate thickness, and the gains of the feedforward control and the feedback control are based on the same evaluation guideline. A rolling mill control method, characterized in that 12. The rolling mill control method according to claim 11, wherein the evaluation guidelines are a rolling mill model and an LQ optimal theory. 13. A rolling mill control method for controlling a rolling mill having a control amount of a delivery side plate thickness and a backward tension, wherein the delivery side plate thickness, the backward tension, a rolling position of a rolling device in the rolling mill, and a rotation of a rolling roll. The operation amount of the actuator such as the rolling device and the rolling roll rotating device that changes the rolling state of the rolling mill from the future history of the plate thickness variation of the rolling material entering the rolling mill in a certain time range, A rolling mill control method comprising adjusting an operation amount of the actuator on the basis of a response waveform of a delivery side plate thickness and a backward tension of the rolling mill.